急性白血病患儿CD4~+CD25~+调节性T细胞和NK细胞免疫作用探讨

目的观察外周血CD4+CD25+调节性T细胞(CD4+CD25+Treg)及自然杀伤细胞(na-ture killer cell,NK)在白血病患儿及非白血病患儿的不同,了解白血病患儿的免疫状态,探讨CD4+CD25+Treg细胞及NK细胞在小儿急性白血病肿瘤免疫中的意义。方法以流式细胞术检测急性白血病初诊患儿及非白血病患儿各30例的外周血CD4+CD25+Treg细胞、NK细胞的数量及比例。结果外周血CD4+CD25+CD127-细胞占CD4+T细胞的比例白血病组为(11.45±1.41)%,显著高于对照组为(6.98±1.09)%(P<0.05)。而NK细胞数量白血病组为(5.13±2.97)%,显著低于对照组为(15.06±3.91)%(P<0.05)。结论 (1)急性白血病患儿外周血CD4+CD25+Treg细胞数量升高,NK细胞数量降低,表明急性白血病患儿NK细胞免疫功能处于抑制状态。CD4+CD25+Treg细胞可能在白血病的发生、发展中起一定作用。(2)通过检测CD4+CD25+CD127-T细胞可较好的反映CD4+CD25+Treg细胞的比例,简便可行、重复性好、检测结果准确、可靠。

Study of CD4+CD25+ regulatory T cells and NK cells in peripheral blood of children with acute leukemia

Objective To investigate the expression features of CD4+CD25+ regulatory T(Treg) cells and NK cells in peripheral blood(PB) of children with acute leukemia(AL),and observe the immune status of patients.The functions of CD4+CD25+ Treg cells and NK cells in leukemia immunity were also explored.Methods The numbers and proportions of CD4+CD25+ Treg cells and NK cells were detected by flow cytometry in PB samples of 30 newly diagnosed(ND) AL patients as well as 30 non-AL children.Results The average proportions of CD4+CD25+CD127-cells to the CD4+ T cells in ND AL patients(11.45±1.41)% were higher than those in non-AL children(6.98±1.09)%.The NK cell counts in AL patients(5.13±2.97)% were lower than those in non-AL children(15.06±3.91%)(P<0.05).Conclusion(1) The expresison features of Treg cells(increased) and NK cells(decreased) in AL patients indicated that the function of NK cells was suppressed.Treg cells may play a certain role in leukemogenesis,and are involved in the down-regulation of NK cells.(2) The application of CD4+D25+CD127-on the detection of Treg cells is simple,reproductive and accurate,which could better reflect the proportions of CD4+CD25+ Treg cells.